South African actress Charlize Theron rolls with the punches as an MI6 agent extraordinaire

Here comes Lorraine Broughton, MI6 agent extraordinaire and the main character of the new movie Atomic Blonde, played with cold ruthlessness and stylish ferocity by Charlize Theron.

Opening here tomorrow, the action thriller is directed by David Leitch of John Wick fame, and that is all you need to know to rush out and buy a ticket.

If you need another reason, there is one tour de force shot that takes the action up and down a staircase, into and out of an apartment, then onto the street and into a car for about five minutes that is worth the price of admission alone.

Adapted from the 2012 graphic novel The Coldest City, Broughton's mission is to find the double agent in Berlin who is hunting operatives on the eve of the collapse of the Berlin Wall in 1989.

She teams up with Berlin station chief David Percival (James McAvoy) to find a defector who has committed the entire list of intelligence assets to memory.

She is a badass heroine who never loses the icy glare, despite the bruises and injuries that would fell a mere mortal.

At our interview at Universal Studios in Universal City, Theron is stylish as usual, this time in an elegant black pantsuit.

Charlize Theron at the premiere of the movie in Berlin on July 17. PHOTO: REUTERS

The 41-year-old South African actress and single mother of two started out by talking about why she took on this passion project, which she also produced.

Said Theron with a laugh: "I think the challenge was the physical storytelling aspect of it. My history as a ballet dancer made me fascinated by that idea.

"There were a lot of mornings where I could not get out of my car. I had valet attendants waiting patiently for me to drag my body out of my car because my quads hurt so badly, and my children made fun of me.

"But then you get past that point and you feel like a machine. Once I hit that place, it gave me great confidence to do more."

Action scenes are typically shot for about two seconds, and a lot of the action really happens in the editing room. But the filming on Atomic Blonde was much more ambitious.

Theron said: "David wanted to shoot continuously for eight to nine seconds at a time, which in the action world is unheard of.

"In order to do that, you can't use a double. So I would say 98 per cent is all me doing it. The staircase scene is all me, except for one fall."

The few times a stunt double - who was one of Theron's trainers - was used was when it did not make sense for her to do it, insurance-wise.

Said Theron: "Because of her, I really understood the female body... You have your opponent in front of you and it is completely unpredictable.

"So in that moment you have to realise, 'Okay, they are... way bigger than me, so I am never going to be able to punch them. I'll break every bone in my hand.'

"So you barely ever see me throw a punch. The one punch that I throw, you see me react to it. So all of my hand-to-hand combat is either elbows, shoulders, knees... things that can't break (easily)."

Still, Theron twisted her knee, bruised her ribs and had to undergo extensive dental surgery because of Atomic Blonde.

"I would be a really good spy," she said with a laugh.

'SELF-COMBUST'

"I think spies are interesting people. When you read about them, you find that a lot of these people could self-combust at any moment.

"That makes for interesting characters to play, because most of them are alcoholics and reckless and rogue, and they have lived in this kind of landscape for so long, they probably could not even function in a normal reality. That is fun as an actor to play."

As for the cool wardrobe, the crew researched Helmut Newton photographs of women of that period in miniskirts and garter belts.

Said Theron: "But to actually put that into reality in a film becomes really challenging.

"The whole fight scene that I have in that apartment is in a miniskirt and garter belts, and our costume designer did a great job because it became super functional and I never knew I was wearing all of that stuff. It just created the character."

Her adopted children - a six-year-old boy and two-year-old girl - were on location with her in Budapest, Hungary.

She said: "We did French hours, which means that you don't break for an hour of lunch. You start work at 9.30am and you are home by 6.30pm.

"In the mornings, I got to send my oldest off to school and change my baby's diaper and feed her her first bottle and get her ready for her day.

"Then I would go to work and I would be home for dinner, so we had a normal family life in Budapest. I loved it."

What Theron was not prepared for was having her little ones show up on set and see her with a prosthetic on her face to suggest she was on the verge of death after getting beaten.

"My oldest understands that my job is pretending. I have done movies where he has seen that, so it was not a shock.

"But I was not quite prepared for this and I had a moment of, 'Oh God, this is going to put them in therapy for the rest of their life.'

"I just said it was Halloween for mum today and that was all I could come up with. And so that passed. Mum gets to go and have Halloween every day," said Theron with a laugh.